The National Institutes of Health (I think) actually has a program regarding cancer-sniffing dogs. They pet out those that don't pass the sniff test (no pun intended). A person in our neighborhood adopted one a few years ago. That being said, it makes sense that other dogs would be able to detect something in other dogs. Again, I am so very sorry for your pain and for Reggie. I really admire the fact that you are able to put his needs above yours. What a terrible weight to bear. May you find comfort in your selfless act.